diff options
Diffstat (limited to 'include/linux/mmu_notifier.h')
| -rw-r--r-- | include/linux/mmu_notifier.h | 12 |
1 files changed, 11 insertions, 1 deletions
diff --git a/include/linux/mmu_notifier.h b/include/linux/mmu_notifier.h index 1d1b1e13f79f..6f32b2b1f76b 100644 --- a/include/linux/mmu_notifier.h +++ b/include/linux/mmu_notifier.h @@ -311,14 +311,24 @@ static inline void mmu_notifier_mm_destroy(struct mm_struct *mm) __young; \ }) +/* + * set_pte_at_notify() sets the pte _after_ running the notifier. + * This is safe to start by updating the secondary MMUs, because the primary MMU + * pte invalidate must have already happened with a ptep_clear_flush() before + * set_pte_at_notify() has been invoked. Updating the secondary MMUs first is + * required when we change both the protection of the mapping from read-only to + * read-write and the pfn (like during copy on write page faults). Otherwise the + * old page would remain mapped readonly in the secondary MMUs after the new + * page is already writable by some CPU through the primary MMU. + */ #define set_pte_at_notify(__mm, __address, __ptep, __pte) \ ({ \ struct mm_struct *___mm = __mm; \ unsigned long ___address = __address; \ pte_t ___pte = __pte; \ \ - set_pte_at(___mm, ___address, __ptep, ___pte); \ mmu_notifier_change_pte(___mm, ___address, ___pte); \ + set_pte_at(___mm, ___address, __ptep, ___pte); \ }) #else /* CONFIG_MMU_NOTIFIER */ |